This application seeks partial funding for a FASEB Summer Research Conference on Phospholipases to be held from July 17- July 22 2004 in Callaway Gardens, Pine Mountain, Georgia. This will be the seventh ASB conference on this subject. The funds requested will be used exclusively to support the registration and travel expenses of junior investigators who will be attending the conference and presenting their work as invited presentations, short talks or posters. The broad goal of this successful and established conference is to provide a form for review and discussion of recent research on the structure, function and regulation of phospholipases which are enzymes that catalyze the hydrolysis of ester and phosphodiester bonds in membrane phospholipids. Members of this widely expressed class of enzymes play central roles in many aspects of cell regulation by producing bioactive lipids and lipid-derived products. Phospholipases A generate fatty acids and lysophospholipids. These enzymes initiate production of receptor-active lipids including lysophosphatidic acid and the eicosanoid metabolites of arachidonic acid and have well established roles in cancer and inflammatory diseases including asthma. Phospholipases C produce inositol phosphate and diglyceride second messengers in response to agonist activation of cell surface receptors and Phospholipases D generate phosphatidic acid from phosphatidylcholine which regulates signaling pathways coupled to control of cell growth, survival, motility and vesicular transport. The conference also includes talks on enzymes that synthesise and degrade sphingolipids that have roles in cellular stress responses and apoptosis as well as a session on analysis of lipid structures by mass spectrometry. This conference brings together scientists with a shared interest in these enzymes that are working in diverse disciplines including biophysics, structural, cell and molecular biology. The conference has a strong record of including presentations from beginning and established investigators and provides an effective forum for promoting collaborations and new advances in the field. The subject area is one that receives considerable support from the NIH with over 400 active projects sustained by funds provided by each of the major NIH institutes. For the past 10 years this field has generated about 2000 peer reviewed research publications each year. The funds requested in this proposal will make an invaluable contribution to the support of this conference.